Last week, we discussed why stormwater detention systems are necessary. As we continue this three part series, we will discuss the different types of stormwater detention systems that are available.
Types of Stormwater Detention Systems
Underground Pipe Systems
|Corrugated Metal Pipe (CMP) System
Oversizing the proposed storm sewer pipes and lowering the slope can facilitate the required stormwater detention. As a greater length of pipe is required to facilitate the storage, the pipe can be designed in a series of runs. The most expensive component of the pipe system is the manifold that connects the runs together. Making the runs longer will reduce the required length of the manifold and keep the cost down. If the existing soils are conducive to infiltration, the pipes can be perforated.
Images courtesy of ADS & Contech
Underground Chamber Systems
Chamber systems can be less expensive than their pipe counterparts as the chamber systems can be installed manually without heavy equipment. The most expensive component of the chamber system is the manifold that connects the runs together. Making the runs longer will reduce the required length of the manifold and keep the cost down. The open bottom of the chamber allows for infiltration of the rain water.
Images courtesy of StormTech
Underground Concrete Vaults
|Cast in Place Concrete Vault System
||Precast Concrete Vault System
While concrete vault systems can be more expensive than their pipe and chamber counterparts, spatially, they can be the most efficient underground detention design, providing the most storage in the tightest space. Concrete vault systems can usually facilitate manual inspections where the pipe and chamber systems can be limited to video inspections.
Images courtesy of WACA & StormTrap
So far, we have discussed why stormwater detention systems are necessary and the different types of systems that are available. In the final part of this series, we will discuss best practices to ensure proper installation and maintenance of your stormwater detention systems.